local voucherId=ARGV[1]

local userId=ARGV[2]

local stockKey="seckill:stock:"..voucherId
local orderKey="seckill:order:"..voucherId
if(tonumber(redis.call("GET",stockKey))<=0)
then
    return 1
end
if(redis.call("SISMEMBER",orderKey,userId)==1)
then
    return 2
end
redis.call("incrby",stockKey,-1)
redis.call("sadd",orderKey,userId)
return 0